Comparison of Oral Administration of Various Doses of Moxidectin and Ivermectin Pour-On Formulations Against Intestinal Parasites in Meat Goats

A total of 64 meat goats (6 months old) were used to investigate the effects of various doses of two anthelmintics on naturally occurring intestinal parasites in two feeding systems (32 animals each). Animals in the extensive system received grazing only and those in the semi-intensive system received grazing plus 1.1 kg of a 12% protein pellet per head per day. Animals in both systems received treatments of Moxidectin (MOX) and Ivermectin (IVM) at 0.275 mg/kg; 0.550 mg/kg and 0.825 mg/kg bodyweight and 0 mg/kg (CONT). Two males and 2 females were randomly assigned to each treatment. A single dose of MOX or IVM was administered orally to each treated animal at Day 0. A fecal sample was taken from each animal on Days 0, 7, 28, 56, and 84 for evaluation of parasite eggs. Body weights were taken on Days 0, 28, 56, and 84. Sampling began on March 8, 2005 and ended on June 15, 2005. In the extensive system, IVM-treated animals (19.95 kg) had a higher average bodyweight gain than those treated with MOX (17.14 kg). MOX-treated animals, 0.550 mg/kg had slightly higher bodyweight gain (5.77 kg) than CONT animals (5.14 kg). In IVM-treated animals, 0.825 mg/kg had the highest bodyweight gain (6 kg). In the semi-intensive system, MOX-treated animals (25.23 kg) had slightly higher average bodyweight gain than IVM-treated (24.64 kg). MOX-treated, 0.825 mg/kg and CONT animals had similar bodyweight gain (6.59 and 6.54 kg). IVMtreated animals, 0.825 mg/kg had the highest bodyweight gain (7.59 kg). Fecal samples showed marked reductions in parasite egg counts in MOX-, IVM-treated and CONT animals for both systems. In the extensive system, MOX-treated animals, had parasite eggs only in animals treated with 0.550 mg/kg whereas IVM-treated animals had no eggs in animals treated with 0.825 mg/kg, and CONT animals at the end of the study. In the semi-intensive system, no parasite eggs were detected in any sample in MOX- treated but were in CONT animals at the end of the study. In IVM-treated animals, 0.550 mg/kg, and CONT animals, no parasite eggs were detected at the end of the study.